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United States Patent |
6,106,485
|
McMahon
|
August 22, 2000
|
Guidewire with shaped intermediate portion
Abstract
A guidewire for advancing a medical device such as a catheter through a
patient's body lumen which has an elongated core with proximal and distal
core sections, a flexible tubular member such as a coil on the distal end
and an intermediate portion, preferably formed at least in part by a
polymeric sheath proximal to the coil having contact regions and recessed
non-contact regions.
Inventors:
|
McMahon; James C. (Temecula, CA)
|
Assignee:
|
Advanced Cardivascular Systems, Inc. (Santa Clara, CA)
|
Appl. No.:
|
972654 |
Filed:
|
November 18, 1997 |
Current U.S. Class: |
600/585; 604/96.01; 604/525 |
Intern'l Class: |
A61B 005/00 |
Field of Search: |
600/585,433,434
|
References Cited
U.S. Patent Documents
3731671 | May., 1973 | Mageoh | 128/2.
|
3928519 | Dec., 1975 | Kashiyama et al. | 264/40.
|
4080706 | Mar., 1978 | Heilman et al. | 29/173.
|
4534363 | Aug., 1985 | Gold | 128/772.
|
4538622 | Sep., 1985 | Samson et al. | 128/772.
|
4724846 | Feb., 1988 | Evans, III | 128/772.
|
4748986 | Jun., 1988 | Morrison et al. | 128/772.
|
4807596 | Feb., 1989 | Hochberger et al. | 128/4.
|
4840623 | Jun., 1989 | Quackenbush | 604/280.
|
5061273 | Oct., 1991 | Yock | 606/194.
|
5095915 | Mar., 1992 | Engelson | 128/772.
|
5135503 | Aug., 1992 | Abrams | 604/164.
|
5147317 | Sep., 1992 | Shank et al. | 604/164.
|
5341818 | Aug., 1994 | Abrams et al. | 128/772.
|
5345945 | Sep., 1994 | Hodgson et al. | 128/772.
|
5358493 | Oct., 1994 | Schweich, Jr. et al. | 604/264.
|
5404887 | Apr., 1995 | Prather | 128/772.
|
5497785 | Mar., 1996 | Viera | 600/585.
|
5507729 | Apr., 1996 | Lindenberg et al. | 604/170.
|
5516336 | May., 1996 | McInnes et al. | 606/194.
|
5551443 | Sep., 1996 | Sepetka et al. | 600/585.
|
5606979 | Mar., 1997 | Hodgson | 128/772.
|
5827201 | Oct., 1998 | Samson et al. | 600/585.
|
Foreign Patent Documents |
0 377 453 A1 | Jul., 1990 | EP.
| |
WO 89/10088 | Nov., 1989 | WO.
| |
WO 92/14508 | Sep., 1992 | WO.
| |
Primary Examiner: O'Connor; Cary
Assistant Examiner: Wingood; Pamela
Attorney, Agent or Firm: Heller Ehrman White & McAuliffe LLP
Claims
What is claimed is:
1. A guidewire for intralumenal advancement of a medical device within a
patient, comprising:
a) an elongated core member which has a proximal core section and a distal
core section, the distal core section having a smooth, non-undulating
exterior surface;
b) a flexible body which is disposed about and secured to a portion of the
distal core section; and
c) an intermediate portion which is disposed proximally adjacent the
flexible body and which has an intermediate sheath disposed about the
distal core section, the intermediate sheath having an exterior surface
with a plurality of undulating contact regions and recessed non-contact
regions disposed between contact regions, the contact regions forming a
plurality of circular ridges, the intermediate sheath having a smooth,
non-undulating interior surface in contact with the exterior surface of
the distal core section.
2. The guidewire of claim 1 wherein recessed non-contact regions are
configured to hold a component selected from the group consisting of a
lubricant, a therapeutic agent and a diagnostic agent.
3. The guidewire of claim 1 wherein the intermediate sheath is formed of a
polymeric material.
4. The guidewire of claim 3 wherein the polymeric material is a heat shrunk
thermoplastic.
5. The guidewire of claim 1 wherein the contact regions comprise about 20
to about 60% of the surface of the intermediate sheath.
6. The guidewire of claim 1 wherein the contact regions are spaced about
0.05 to about 5 mm.
7. The guidewire of claim 1 wherein the contact regions are spaced about
0.1 to about 0.5 mm.
8. The guidewire of claim 1 wherein the recessed non-contact regions have
depths of about 0.01 to about 0.1 mm.
9. The guidewire of claim 1 wherein the recessed non-contact regions have
depths of about 0.025 to about 0.075 mm.
10. The guidewire of claim 1 wherein the intermediate sheath has a proximal
portion with an outer diameter approximately the same as the outer
diameter of the proximal core section.
11. The guidewire of claim 1 wherein the intermediate sheath has a distal
portion with an outer diameter approximately the same as an outer diameter
of the flexible body.
12. The guidewire of claim 1 wherein the intermediate sheath is about 4 to
about 38 cm in length.
13. The guidewire of claim 1 wherein the intermediate sheath is about 6 to
about 20 cm in length.
14. A guidewire for intralumenal advancement of a medical device within a
patient, comprising:
a) an elongated core member which has a proximal core section and a distal
core section, the distal core section having a smooth, non-undulating
exterior surface;
b) a flexible body which is disposed about and secured to a portion of the
distal core section; and
c) an intermediate portion which is disposed proximally adjacent the
flexible body and which has an intermediate sheath disposed about the
distal core section, the intermediate sheath having a closed figure
texture formed in an exterior surface thereof with contact regions forming
an edge surrounding non-contact regions, the non-contact regions being
configured to hold a component selected from the group consisting of a
lubricant, a therapeutic agent and a diagnostic agent, the intermediate
sheath having a smooth, non-undulating interior surface in contact with
the exterior surface of the distal core section.
15. The guidewire of claim 12 wherein the intermediate sheath is formed of
a polymer.
Description
BACKGROUND OF THE INVENTION
This invention relates to the field of guidewires for advancing
intravascular devices such as stent delivery catheters, balloon dilatation
catheters and atherectomy catheters within a body lumen.
Conventional guidewires for angioplasty, stent delivery, atherectomy and
other vascular procedures usually comprise an elongated core member with
one or more tapered sections near the distal end thereof and a flexible
body such as a helical coil or a tubular body of polymeric material
disposed about the distal portion of the core member. A shapable member,
which may be the distal extremity of the core member or a separate shaping
ribbon which is secured to the distal extremity of the core member extends
through the flexible body and is secured to the distal end of the flexible
body by soldering, brazing or welding which forms a rounded distal tip.
Torquing means are provided on the proximal end of the core member to
rotate, and thereby steer, the guidewire while it is being advanced
through a patient's vascular system.
Further details of guidewires, and devices associated therewith for various
interventional procedures can be found in U.S. Pat. No. 4,748,986
(Morrison et al.); U.S. Pat. No. 4,538,622 (Samson et at.): U.S. Pat. No.
5,135,503 (Abrams); U.S. Pat. No. 5,341,818 (Abrams et al.); and U.S. Pat.
No. 5,345,945 (Hodgson, et al.) which are hereby incorporated herein in
their entirety by reference thereto.
In a typical coronary procedure using a guidewire, a guiding catheter
having a preformed distal tip is percutaneously introduced into a
patient's peripheral artery, e.g. femoral or brachial artery, by means of
a conventional Seldinger technique and advanced and steered therein until
the distal tip of the guiding catheter is seated in the ostium of a
desired coronary artery.
There are two basic techniques for advancing a guidewire into the desired
location within the patient's coronary anatomy through the in place
guiding catheter. The first is a preload technique which is used primarily
for over-the-wire (OTW) devices and the second is the bare wire technique
which is used primarily for rail type systems.
With the preload technique, a guidewire is positioned within an inner lumen
of an OTW device such as a dilatation catheter or stent delivery catheter
with the distal tip of the guidewire just proximal to the distal tip of
the catheter and then both are advanced through the guiding catheter to
the distal end thereof. The guidewire is first advanced out of the distal
end of the guiding catheter into the patient's coronary vasculature until
the distal end of the guidewire crosses the arterial location where the
interventional procedure is to be performed, e.g. a lesion to be dilated
or a dilated region where a stent is to be deployed. The catheter, which
is slidably mounted onto the guidewire, is advanced out of the guiding
catheter into the patient's coronary anatomy over the previously
introduced guidewire until the operative portion of the intravascular
device, e.g. the balloon of a dilatation or a stent delivery catheter, is
properly positioned across the arterial location. Once the catheter is in
position with the operative means located within the desired arterial
location, the interventional procedure is performed. The catheter can then
be removed from the patient over the guidewire. Usually, the guidewire is
left in place for a period of time after the procedure is completed to
ensure reaccess to the arterial location is it is necessary. For example,
in the event of arterial blockage due to dissected lining collapse, a
rapid exchange type perfusion balloon catheter such as described and
claimed in U.S. Pat. No. 5,516,336 (Mclnnes et al), can be advanced over
the in-place guidewire so that the balloon can be inflated to open up the
arterial passageway and allow blood to perfuse through the distal section
of the catheter to a distal location until the dissection is reattached to
the arterial wall by natural healing.
With the bare wire technique, the guidewire is first advanced by itself
through the guiding catheter until the distal tip of the guidewire extends
beyond the arterial location where the procedure is to be performed. Then
a rail type catheter, such as described in U.S. Pat. No. 5,061,395 (Yock)
and the previously discussed Mclnnes et al. which are incorporated herein
by reference, is mounted onto the proximal portion of the guidewire which
extends out of the proximal end of the guiding catheter which is outside
of the patient. The catheter is advanced over the catheter, while the
position of the guidewire is fixed, until the operative means on the rail
type catheter is disposed within the arterial location where the procedure
is to be performed. After the procedure the intravascular device may be
withdrawn from the patient over the guidewire or the guidewire advanced
further within the coronary anatomy for an additional procedure.
SUMMARY OF THE INVENTION
The present invention is directed to an improved guidewire having a
flexible distal section which facilitates advancement through a patient's
body lumen.
The guidewire of the present invention has an elongated core member with
proximal and distal core sections with a flexible tubular member such as a
helical coil is disposed about and secured to the distal part of the
distal core section. The distal core section has one or more distally
tapering segments. Proximal to the flexible tubular member, the guidewire
has an exterior surface which is shaped to provide a plurality of contact
regions and non-contact regions between adjacent contact regions.
In one presently preferred embodiment, the intermediate portion is defined
by a sheath disposed about the core member and preferably formed of a
polymeric material. The contact region or regions of the intermediate
portion of the guidewire is generally about 20 to about 60% of the surface
of the sheath. The outer diameter of the contact regions of the
intermediate portion is preferably the same or approximately the same as
the outer diameter of the flexible tubular member or coil on the distal
part of the distal shaft section. However, if the flexible tubular member
is of different outer diameter than the proximal core section, the
intermediate portion may taper from the outer diameter of the proximal
core section to the outer diameter of the coil. The distances between the
peaks of the contact regions should be about 0.05 to about 5.0 mm,
preferably about 0.1 to about 0.5 mm. The depth of the recessed
non-contact regions may be about 0.01 to about 0.1 mm, preferably about
0.025 to about 0.075 mm as measured from the peaks of the contact regions.
While the presently preferred intermediate portion of the guidewire having
the contact and non-contact regions extends distally from the flexible
tubular member and terminates distal to the proximal core section, the
section having the contact and non-contact regions can extend proximally
over most or all of the proximal core section.
By reducing the area of surface contact between the guidewire and a body
lumen or a catheter lumen in which the guidewire is being moved relative
thereto, the resistance to movement is greatly reduced. In one embodiment
of the invention, solid or liquid lubricant can be maintained within
recessed non-contact regions to further reduce frictional drag on the
guidewire as it moves through a lumen or the frictional drag on a catheter
as the catheter is moved over the intermediate portion of the guidewire.
Pharmaceutical materials and diagnostic and therapeutic agents may also be
incorporated into the recessed non-contact regions.
In one presently preferred embodiment of the invention, the intermediate
guidewire portion having the contact and non-contact regions is defined by
an intermediate sheath disposed about at least part of the distal
guidewire section proximal to the flexible tubular member or coil on the
distal part of the distal section.
These and other advantages of the invention will become more apparent from
the following detailed description of the invention when taken in
conjunction with the accompanying exemplary drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view partially in section of a guidewire embodying
features of the invention wherein a sheath forming the intermediate
portion has a helically shaped ridge.
FIG. 2 is a transverse cross-sectional view of the guidewire shown in FIG.
1 taken along the lines 2--2.
FIG. 3 is a transverse cross-sectional view of the guidewire shown in FIG.
1 taken along the lines 3--3.
FIG. 4 is an elevational view partially in section of an alternative
embodiment of the invention wherein a sheath on the intermediate portion
has an undulating exterior surface.
FIG. 5 is a transverse cross-sectional view of the embodiment shown in FIG.
4 taken along the lines 5--5.
FIG. 6 is an elevational view partially in section of an alternative
embodiment of the invention wherein the intermediate section has a closed
figure design formed into the exterior surface thereof.
FIG. 7 is a transverse cross-sectional view of the embodiment shown in FIG.
6 taken along the lines 7--7.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1-3 depict a guidewire 10 embodying features of the invention which
has an elongated core member 11 with a proximal core section 12, a distal
core section 13 and a helical coil 14 on the distal extremity of the
distal core section. An intermediate portion of the guidewire 10 proximal
to the helical coil 14 is provided with a sheath 15, which is disposed
about and secured to the distal core section 13, has an exterior surface
16 with contact regions 17 in the form of a helical ridge and a plurality
of recessed (with respect to the contact regions) non-contact regions 18
disposed between adjacent contact regions. The peak-to-peak distance
between the adjacent contact regions 17 is about 0.05 to about 5 mm,
preferably about 0.1 to about 0.5 mm.
The distal end of coil 14 is secured to the distal tip of the distal core
section 13 by suitable means, such as solder, a weldment, an adhesive, a
body of polymeric material and the like which forms the rounded tip 20.
The proximal end of the coil 14 is secured to the distal core section by
solder 21. The proximal core section 12 has a polymeric jacket 22 which is
preferably formed of lubricious polymeric materials such as fluoropolymers
or hydrophilic materials. Other lubricious materials may be utilized.
An alternative embodiment of the invention is depicted in FIGS. 4 and 5
wherein the guidewire 30 has an intermediate portion proximal to the
helical coil (not shown) covered with a sheath 32 which has an undulating
exterior surface 33 with contact regions 34 in the form of a plurality of
circular ridges and a plurality of recessed non-contact regions 35 between
adjacent contact regions. The peak-to-peak distances between the contact
surfaces 34 of this embodiment are the same or approximately the same as
that for the contact regions 17 of the previously described embodiment.
FIGS. 6 and 7 illustrate yet another alternative embodiment of the
invention in which the guidewire 40 has an intermediate portion with a
sheath 41 with a closed figure texture formed in the exterior surface 42
with contact regions 43 and recessed non-contact regions 44 for
essentially the same purpose as the contact and non-contact regions of the
previously discussed embodiments. The recessed non-contact regions may
contain liquid or solid lubricant such as a fluoropolymer, a silicone
coating such as MICROGLIDE.TM., or HYDROCOAT.TM.. These recesses may also
be employed as reservoirs for pharmaceutical materials, therapeutic agents
or diagnostic agents.
The sheaths forming the intermediate portions of the guidewires of the
present invention may be formed by first heat shrinking a thermoplastic
polymeric material onto the distal core section proximal to the coil and
then placing a clam-shell mold of the desired configuration about the heat
shrunk material at elevated temperatures to shape the exterior of the
intermediate sheath in the desired configuration. Other means may also be
employed. For example, the exterior surface of a tubular polymeric member
may first be formed into the desired shape and then the tubular member
heat shrunk onto the distal core section. Other means including casting
polymeric material about the distal core section into the desired shape.
Machining polymeric material from the exterior of a tubular polymeric
member on the distal core segment may also be employed to develop the
contact and non-contact regions of the intermediate sheath. Suitable
polymeric materials for the intermediate sheath include polyethylene,
polyetheretherketone, polyvinyl chloride and polyurethane. A wide variety
of other polymeric materials are contemplated. The sheathed intermediate
portion of the guidewire is about 4 to about 38 cm in length, preferably
about 6 to about 20 cm in length.
The guidewires of the invention may have typical guidewire dimensions.
Guidewire length may generally be about 90 to about 300 cm, and for use
within a patient's coronary anatomy commercially available guidewires are
typically about 175 cm in length. Recently, however, longer guidewires,
e.g. up to 190 cm in length, are being offered commercially by a variety
of suppliers, including the present assignee. The proximal core section 12
may have a length of about 65 to about 280 cm, preferably about 150 to
about 200 cm and a diameter generally about 0.008 to about 0.035 inch
(0.20-0.89 mm), typically about 0.01 0 to about 0.020 inch (0.25-0.51 mm)
for coronary artery uses. The distal core section is preferably much
shorter than the proximal core section and generally is about 6 to about
40 cm, preferably about 8 to about 30 cm in length and tapers in the
distal direction in one or more steps to smaller transverse dimensions.
The core member is preferably coated with a lubricous coating such as a
fluoropolymer, e.g. TEFLON.RTM. available from DuPont, which extends the
length of the proximal core section 12. The distal section 13 is also
provided a lubricous coating, not shown for purposes of clarity, such as a
MICROGLIDE.TM. coating used by the present assignee, Advanced
Cardiovascular Systems, Inc. on many of its commercially available
guidewires.
The tapered portion of the distal core segment is preferably followed
distally with a manually shapable flattened core segment or shaping ribbon
of about 1 to 4 cm in length which preferably has essentially constant
transverse dimensions, e.g. 0.0005-0.002 inch (0.013-0.051 mm) by
0.002-0.006 inch (0.051-0.152 mm), typically about 0.001 by 0.003 inch
(0.025-0.076 mm). A helical coil having transverse outer dimensions about
the same as or slightly less than the proximal core section is secured by
its distal end to the flattened distal tip of the core member, e.g. by
means of solder, and by its proximal end at an intermediate position on
the tapered distal core segment so that the distal end of the tapered core
segment resides within the interior of the coil. The helical coil 14 may
be formed all or in part of stainless steel, a suitable radiopaque
material such as platinum or alloys thereof or other material such as
stainless steel coated with a radiopaque material such as gold. The wire
from which the coil is made generally has a transverse diameter of about
0.0015 to about 0.003 inch (0.04-0.08 mm) for coronary applications and up
to 0.07 inch (0.18 mm) for peripheral applications. The overall length of
the coil 14 is about 2 to about 15 cm, preferably about 2 about 6 cm.
Multiple turns of the coil 14 may be expanded to provide additional
flexibility.
Unless otherwise described herein, conventional materials and manufacturing
methods may be used to make the guiding members of the present invention.
Additionally, various modifications may be made to the present invention
without departing from the scope thereof. Although individual features of
embodiments of the invention may be shown in some of the drawings and not
in others, those skilled in the art will recognize that individual
features of one embodiment of the invention can be combined with any or
all the features of another embodiment.
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